Since I have cartridge filters, am I correct is assuming that my CH and borate levels should not wavier much?
CH and Borate levels
- Thread starter TroyB
- Start date
Hi, Troy,
To my knowledge, filter type has no relevance on CH or borate levels. I may have overlooked something there but I don't think so.
CH and borates are, for the most part, stable in your pool other than the affects of splashout and refills.
To my knowledge, filter type has no relevance on CH or borate levels. I may have overlooked something there but I don't think so.
CH and borates are, for the most part, stable in your pool other than the affects of splashout and refills.
duraleigh said:
I was referring to the fact that since I don't backwash my filters, refills of the pool should be minimized (except for splashout).
I understand now.
Yeah, you'll have no issues. My guess would be only a very small pool with a lot of backwashing would be about the only case where it might have a significant effect.
Yeah, you'll have no issues. My guess would be only a very small pool with a lot of backwashing would be about the only case where it might have a significant effect.
spishex said:
Interestingly enough, my CYA levels have dropped over the winter. I measured CYA of 60 during early fall and I recently read 40.
I will bring back up to 60 - 70 in the spring. I'm really not worried about it until we start swimming again! :-D
There's been some talk on the forum and elsewhere about CYA disappearing during the winter. Back in my pool store days we were told by Bioguard that CYA levels shouldn't be tested during spring startup until after the pool was shocked because combined chlorine levels had a way of masking the CYA levels (or the test itself). I'm still waiting on an answer from them as to why that is. Nobody else seems to have heard that tale and there are only a few vague references to it on the web.
There were some other theories discussed in the deep end, and I think most of them had to do with cold weather months. I'll add to them if I ever get an answer from Biolab.
Long story short, CYA shouldn't move that much unless you lose water (or add more CYA).
Here's the in-depth thread.
There were some other theories discussed in the deep end, and I think most of them had to do with cold weather months. I'll add to them if I ever get an answer from Biolab.
Long story short, CYA shouldn't move that much unless you lose water (or add more CYA).
Here's the in-depth thread.
There are two different effects going on. CYA can vanish permanently over the winter. CYA tests can also read incorrectly during the winter and first thing after spring startup. Give the water at least 24 hours to circulate after you open in the spring and warm up your sample to indoor room temperature before doing your first spring CYA test.
gtm
LifeTime Supporter
waterbear said:
Is it possible to quantify that dependency? I recently did the ascorbic acid thing and the pool clouded badly, requiring two backwashes and two vacuums out to waste. My CYA reading dropped 10 ppm (60 to 50), which seems right for the amount of water I lost, but I frankly don't trust the measurement to that level of precision.
The pool temperature also dropped by 10 degrees during that time. Is is possible that I'm still at 60 ppm but was fooled by the temperature change? I should also tell you that I didn't take the sample inside to warm up, but outside at that time was 60 degrees for the water and 75 degrees for the air temperature.
Thanks, Gary
It's going to be hard to quantify. The CYA tests adds melamine to the water which forms a precipitate compound, melamine cyanurate, that has a solubility of 20 ppm. In order to force more precipitate, the test uses an acid pH buffer which forces most of this compound to precipitate since it is far less soluble in acidic conditions. In theory, there shouldn't be a lot of temperature dependence since most of the CYA should already be precipitated.
You could probably do a simple experiment to see the temperature dependence for yourself. You could take a sample of a CYA test mixture and view it after subjecting the sample to room temperature, refrigeration (about 35F), and brief microwaving (to make it hot). It would be interesting to see the results. I'd do it myself, but my pool right now has rather low CYA near 20 ppm so isn't in a good midpoint range for testing.
Richard
You could probably do a simple experiment to see the temperature dependence for yourself. You could take a sample of a CYA test mixture and view it after subjecting the sample to room temperature, refrigeration (about 35F), and brief microwaving (to make it hot). It would be interesting to see the results. I'd do it myself, but my pool right now has rather low CYA near 20 ppm so isn't in a good midpoint range for testing.
Richard
gtm
LifeTime Supporter
Sounds like fun, and has the added benefit of making my wife question my sanity. She'll have a great time telling all of her friends about it.chem geek said:
I'll report back in a few days. Hopefully from the same address ...
The temperature dependence has more to do with reaction time than solubility. I have seen the test take as long as 10 minutes with a cold sample. I have had customers with stable CYA that I would see weekly and then we get a cold snap and their water temp has dropped from, say, 75 to 60 and I see the CYA levels seem to have dropped unless I allow a much longer reaction time for the test. If I do the CYA levels are still constant.
From my experience with a good majority of regular customers it can take 10 minutes or longer with a cold sample to get an accurate reading.
From my experience with a good majority of regular customers it can take 10 minutes or longer with a cold sample to get an accurate reading.
gtm
LifeTime Supporter
Thanks waterbear, that's nice to know. As you've probably also seen in Jax, our temperatures here in St. Pete dropped about 10 degrees over the past two weeks. I don't recall, however, how long I waited before taking the reading. I'll try it again and report back.
On the other hand, the 10 ppm drop is consistent with the amount of water I had to drain while cleaning out the cloudiness following the ascorbic acid treatment. We'll see.
Please note, however, that I'll probably start a new thread when I report back. I'm getting a little worried that I'm "hijacking" this one.
Gary
On the other hand, the 10 ppm drop is consistent with the amount of water I had to drain while cleaning out the cloudiness following the ascorbic acid treatment. We'll see.
Please note, however, that I'll probably start a new thread when I report back. I'm getting a little worried that I'm "hijacking" this one.
Gary
gtm said:
No worries...I'm curious as to your upcoming experiment. Please post your findings!
gtm
LifeTime Supporter
Thanks TroyB. I'll continue this thread then, but it'll be a little while. I'm a single father for the next few days and keeping up with the 9-year old is running me ragged ... Cheers, Gary
gtm
LifeTime Supporter
I haven't had time to do the full experiment yet, but today I checked Evan/waterbear's suggestion about the time to allow before doing the test. Water temp is 62 and the air temp today was almost the same.
I made up the test solution, mixed for 30 seconds according to instructions and then did 5 reps of the test. A rep means I did a reading, poored back into the bottle, shook for a few seconds, and then tested again. All together this series took about 4-5 minutes.
The 5 readings were as follows. First was very near the 30 mark, second was about midway between 30 and 40, third was just below (closer to 30) 40, and the last two were both just over 40. I wouldn't trust the absolute values, but I'm pretty sure the dot was "obscured" to the same level each time, at least according to my eye.
I then shook the (same) bottle of solution for 10 minutes. I was careful to hold it on the ends and not in my fist, so I doubt that the temperature changed very much. Remember that the air and pool temperature were nearly identical.
I then read 5 times again, same procedure as above, and got the exact same "just over 40" reading that I saw on the last two reps from before. Actually, I was sort of surprised how reproducible the results were.
Based on this woefully inadequate experiment, I've decided that in the future, regardless of the temperature, I'm going to mix for 5 minutes or so before doing the test. The 30 seconds called for in the Taylor instructions seems too short, at least for today's test.
I'll do the experiment Richard/chemgeek suggested as soon as I can and report back.
Cheers, Gary
I made up the test solution, mixed for 30 seconds according to instructions and then did 5 reps of the test. A rep means I did a reading, poored back into the bottle, shook for a few seconds, and then tested again. All together this series took about 4-5 minutes.
The 5 readings were as follows. First was very near the 30 mark, second was about midway between 30 and 40, third was just below (closer to 30) 40, and the last two were both just over 40. I wouldn't trust the absolute values, but I'm pretty sure the dot was "obscured" to the same level each time, at least according to my eye.
I then shook the (same) bottle of solution for 10 minutes. I was careful to hold it on the ends and not in my fist, so I doubt that the temperature changed very much. Remember that the air and pool temperature were nearly identical.
I then read 5 times again, same procedure as above, and got the exact same "just over 40" reading that I saw on the last two reps from before. Actually, I was sort of surprised how reproducible the results were.
Based on this woefully inadequate experiment, I've decided that in the future, regardless of the temperature, I'm going to mix for 5 minutes or so before doing the test. The 30 seconds called for in the Taylor instructions seems too short, at least for today's test.
I'll do the experiment Richard/chemgeek suggested as soon as I can and report back.
Cheers, Gary
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